Impact of Cover Crop Species Diversity on Soil Nutrient Availability and Crop Productivity

Cover crops provide multiple environmental benefits that improve both soil and water quality; however, farmers only utilize them on approximately 5% of harvested U.S. cropland. Low adoption rates are attributed to yield impact concerns, seed and planting costs, and lack of advocacy. This study, which began in October 2019, assessed the effects of nitrogen rate and cover crop diversity on weed biomass, soil coverage, in-situ residue decomposition, soil nitrogen and phosphorus availability, and cash crop yield to better understand the costs and benefits of cover crop adoption at two locations in Tennessee (Milan and Spring Hill). Treatments were replicated 4 times in a split-plot design and consisted of four nitrogen rates (0, 112, 164, 224 kg N ha-1) and five cover crop treatments (fallow, winter wheat, crimson clover, wheat-clover bi-culture, and a five-species “soil health mix” that consisted of wheat, oats, clover, hairy vetch, daikon radish). Results indicated that increased cover crop diversity provided better weed control and soil coverage as well as providing more consistent biomass with less annual variability. Diverse mixtures improved residue decomposition, which controlled overall nutrient release, and provided a source of supplemental nitrogen comparable to the clover monoculture. Of all cover strategies, none provided enough nitrogen or phosphorus to justify reducing fertilizer application, and there were significant, negative impacts on yield under nitrogen-limited conditions to impact profitability. Cover cropping alone did not increase profitability alone; however, participation in cost-share programs and additional revenue such as forage sales have the potential to improve financial sustainability. Regardless of cover crop selected, sufficient biomass production was the most influential factor in cover crop success and was most impacted by planting and termination date; however, increased diversity did somewhat alleviate these constraints

Assessing the Reactive Oxidant Potential of Isoprene-Derived Epoxides and Secondary Organic Aerosol

Fine particulate matter (PM2.5) is an ensemble of particles suspended in air that are at least 2.5 microns or smaller in diameter and are known to contribute to adverse health effects, such as asthma and cardiopulmonary disease. PM2.5 can be directly emitted into the atmosphere by anthropogenic sources, such as motor vehicles, power plants, and factories. Biogenic sources also can contribute to the formation of PM2.5, especially isoprene (2-methyl-1,3-butadiene), a volatile organic compound (VOC) of interest in this study. Secondary organic aerosol (SOA) is a major component of PM2.5 and can be produced from the atmospheric oxidation of biogenic VOCs in the presence of anthropogenic pollutants such nitrogen oxides and sulfur dioxide. However, whether biogenic SOA contributes to adverse health effects remains unclear. The objective of this study was to assess the reactive oxidant potential of isoprene-derived epoxides and SOA. The dithiothreitol (DTT) assay was used to characterize the reactive oxygen species (ROS) generation potential of individual isoprene-derived epoxides and their hydrolysis products, including isoprene epoxydiols (IEPOX), methacrylic acid epoxide (MAE), 2- methyltetrols (2-MT), and 2-methylglyceric acid (2-MG), and of SOA produced from photooxidation and reactive uptake experiments with isoprene, methacrolein (MACR), IEPOX, and MAE as precursors. It was found that 2-MG, MAE and MACR-derived SOA possess a higher oxidant generation potential compared to the 2-MT, IEPOX and isoprene-derived SOA system. Compared to prior studies with diesel exhaust PM, MAE and MACR-derived SOA show the same or higher ROS generation potential, and thus, highlights the need for more studies to further characterize SOA toxicity from this source.Bachelor of Science in Public Healt

Soldiers as Victims at the ECCC: Exploring the Concept of ‘Civilian’ in Crimes against Humanity

AbstractThe inspiration for this article came from a call for amicus curiae briefs issued in April 2016 by the Office of the Co-Investigating Judges in the Extraordinary Chambers in the Courts of Cambodia (ECCC). The call sought guidance on: whether, under customary international law applicable between 1975 and 1979, an attack by a state or organization against members of its own armed forces may amount to an attack directed against a civilian population for the purpose of constituting a crime against humanity under Article 5 of the ECCC Law. We argue that customary international law justifies a finding that an attack on members of the armed forces can constitute crimes against humanity. In particular, the article focuses on the importance placed on the persecution element of crimes against humanity in the post-Second World War jurisprudence, and the broad interpretation of the term ‘civilian’. The article also examines the jurisprudence of contemporary international courts, finding that in some cases the courts have interpreted the term ‘civilian’ as incorporating hors de combat. However, the International Criminal Tribunal for the former Yugoslavia (ICTY) and International Criminal Court (ICC) have moved towards a more restrictive interpretation of the term ‘civilian’, potentially excluding members of the armed forces. We argue that this move is regressive, and against the spirit in which the offence of crimes against humanity was created. The ECCC has an opportunity to counter this restrictive approach, thereby narrowing the protection gap which crimes against humanity were initially created to close.</jats:p

Implicit Positivity: Improving Mood with Environmental Cues

Research in recent years has touted the benefits of positive emotions. However, new studies suggest that actively trying to be positive can backfire, leaving a person feeling worse than before. In this study, the efficacy of implicit goals of positivity as an alternate mechanism for mood improvement was investigated. All participants completed a negative mood induction before completing a thought task while being exposed to either positive or neutral environmental cues. During the task, participants were either asked to try to “improve their mood” or to list whatever thoughts came to their mind. A variety of measures, including number of thoughts, thought automaticity, thought valence, and degree of mood repair were collected across conditions. Despite research to the contrary, most participants experienced greater positivity when given an explicit goal to try to be positive. However, among participants prone to rumination, implicit goals were comparatively more effective in generating positivity. Though the implicit mechanism of environmental cues may not be effective for all people, it seems to be preferable for those with a tendency to dwell on negative thoughts. The possibilities for follow-up research and for practical applications of such findings are discussed.Bachelor of Scienc

David Doellinger Interview 2022

In this interview, David Doellinger describes the WOU Fallout Shelter (which was dismantled in 2022) and discusses the importance of the history of the Cold War. A physical exhibit detailing the history of WOU\u27s Fallout Shelter was created by History 404l students during Fall 2022 and captured in a PowerPoint presentation. The presentation is also included on this page

Development of a Full-Thickness Human Skin Equivalent In Vitro Model Derived from TERT-Immortalized Keratinocytes and Fibroblasts

Currently, human skin equivalents (HSEs) used for in vitro assays (e.g., for wound healing) make use of primary human skin cells. Limitations of primary keratinocytes and fibroblasts include availability of donor skin and donor variation. The use of physiologically relevant cell lines could solve these limitations. The aim was to develop a fully differentiated HSE constructed entirely from human skin cell lines, which could be applied for in vitro wound-healing assays. Skin equivalents were constructed from human TERT-immortalized keratinocytes and fibroblasts (TERT-HSE) and compared with native skin and primary HSEs. HSEs were characterized by hematoxylin-eosin and immunohistochemical stainings with markers for epidermal proliferation and differentiation, basement membrane (BM), fibroblasts, and the extracellular matrix (ECM). Ultrastructure was determined with electron microscopy. To test the functionality of the TERT-HSE, burn and cold injuries were applied, followed by immunohistochemical stainings, measurement of reepithelialization, and determination of secreted wound-healing mediators. The TERT-HSE was composed of a fully differentiated epidermis and a fibroblast-populated dermis comparable to native skin and primary HSE. The epidermis consisted of proliferating keratinocytes within the basal layer, followed by multiple spinous layers, a granular layer, and cornified layers. Within the TERT-HSE, the membrane junctions such as corneosomes, desmosomes, and hemidesmosomes were well developed as shown by ultrastructure pictures. Furthermore, the BM consisted of a lamina lucida and lamina densa comparable to native skin. The dermal matrix of the TERT-HSE was more similar to native skin than the primary construct, since collagen III, an ECM marker, was present in TERT-HSEs and absent in primary HSEs. After wounding, the TERT-HSE was able to reepithelialize and secrete inflammatory wound-healing mediators. In conclusion, the novel TERT-HSE, constructed entirely from human cell lines, provides an excellent opportunity to study in vitro skin biology and can also be used for drug targeting and testing new therapeutics, and ultimately, for incorporating into skin-on-a chip in the future

VOEvent Standard for Fast Radio Bursts

Fast radio bursts are a new class of transient radio phenomena currently detected as millisecond radio pulses with very high dispersion measures. As new radio surveys begin searching for FRBs a large population is expected to be detected in real-time, triggering a range of multi-wavelength and multi-messenger telescopes to search for repeating bursts and/or associated emission. Here we propose a method for disseminating FRB triggers using Virtual Observatory Events (VOEvents). This format was developed and is used successfully for transient alerts across the electromagnetic spectrum and for multi-messenger signals such as gravitational waves. In this paper we outline a proposed VOEvent standard for FRBs that includes the essential parameters of the event and where these parameters should be specified within the structure of the event. An additional advantage to the use of VOEvents for FRBs is that the events can automatically be ingested into the FRB Catalogue (FRBCAT) enabling real-time updates for public use. We welcome feedback from the community on the proposed standard outlined below and encourage those interested to join the nascent working group forming around this topic.Comment: 11 pages, 2 figures, parameter definition table in appendi